(The works were not called TR until the publishers preface in the 1633 Elzevir printing read, "textum ergo habes, nunc ab omnibus receptum," translated "so you hold the text, now received by all." The KJV was primarily translated from the 1550 Stephanus "Editio Regia" printing of the TR.)

There were numerous revisions printed after 1516. Most notably was the 3rd Edition which included the Comma Johanneum. The Comma Johanneum is a comma, or short clause, present after the 3rd Edition of the TR and subsequently in the KJV. Erasmus "was the first to discover that the words in 1 John [5] v. 7,8, "In heaven, the Father, the Word, and the Holy Ghost, and these three are one. And there are three that bear witness in earth," are not genuine, and that the passage should stand thus: "For there are three that bear record, the Spirit, and the water, and the blood, and these three agree in one." Erasmus had, however, pledged himself in his controversy with Lee, to insert the words if they existed in one Greek manuscript. A Codex Britannicus, written probably under Lee's direction, was at length found which contained them. Then Erasmus, for the sake of peace, published the words in the third edition." - The life and character of Erasmus (pg 174) - A.R. Pennington

In Colossians 1:14, we find the clause "through his blood." According to one of the scholars I asked, there are only 9 relatively late (none prior to AD 800) Greek Manuscripts that support the reading that contains "through his blood." This is such a small number that no scholar would consider it original. In all likelihood, one of these manuscripts was used by Erasmus in compiling the TR. (It should be noted that the omission of "through his blood" in no way diminishes doctrine, as it is stated without controversy in Col. 1:20, and again in Ephesians 1:7.)

In Acts 8:37, Philip asks the Ethiopian for a testimony before baptizing him. The verse, with its many variations, first appears in the earliest Latin versions and seems to have made its way into the TR from there. Neither the Majority Text nor the Alexandrian texts contain the verse, but Erasmus found it in the margin of one of his manuscripts and included it in the TR likely because he suspected it was an accidental omission (marginal gloss).

I could stop there and argue that if even one of these verses is corrupt, it proves the Textus Receptus is corrupt and thereby the KJV is corrupt.

The TR was not, in fact, just the New Testament in Greek, but also included Erasmus' attempt to translate it into Latin. "His translations from Greek are wanting in accuracy, because he lived in an age in which there were no dictionaries, and no good editions of the Greek authors. We are quite willing, too, to admit that as we might have expected, the Greek text, having been brought out when the study of Greek had only just commenced in Europe, is very imperfect, and will not stand the test of modern criticism. Still we may venture to affirm that his notes contain many exact philological remarks, founded on a knowledge of the Greek language, of the style of the Scriptures, and of the doctrine of the Fathers, and that though he has been surpassed by many men inferior to him in ability and industry, who lived at a time when critical knowledge was very generally cultivated, yet he must have the merit given him of having been the pioneer in that work of criticism which has shed a bright light on many parts of the records of heavenly truth." - The life and character of Erasmus (pg 174-175) - A.R. Pennington

The reading of the majority of Greek manuscripts differs from the TR in 1,838 places. More than half (1005) are considered "translatable differences." The remainder would make no difference when translated to English. The majority of manuscripts agree against the TR in excluding Luke 17:36, Acts 8:37, and the Comma Johanneum from the New Testament, as well as concurring in numerous other readings (such as "tree of life" in Revelation 22:19, and omitting "through his blood" from Col. 1:14). This fact is the reason modern translations have all but abandoned the TR.